Back on topic, here are some improvements for Crazy:
Crazy 1: 4 Blockers + 4 Diggers
Crazy 8: 4 Builders + 2 Bashers (I wouldn't rule out 1 basher, though)
Crazy 12: 2 Builders + 4 Bashers
Crazy 15: 3 Builders + 1 Digger (the min-skills solution is good for 100%)
Crazy 19: 5 Builders + 1 Basher + 1 Digger
Crazy 20: 14 Builders + 1 Basher (I'm pretty sure the builders can be reduced further, but I don't feel like messing with it right now.)
Also, You need 4 builders for Wild 5, which is not noted on the result for that level.
Crazy 8 4 Builders: 2 builders are used to get over the water and 2 more are used to get up to the exit. If you start the final basher in the right place, you won't need a builder to stop him (ccexplore's basher planning tutorial helps a bunch here).
Crazy 12 2 Builders: Start your first basher as far left as possible and set the RR to 99. As soon as the basher breaks through, place a blocker at the extreme edge, which should be raised one pixel due to the basher's stroke. One lemming must go past to clear the rest of the route, and the original basher (who takes one more stroke because he is on an even number) will bounce off the blocker. When the route is clear, bash away the pixel the blocker is standing on.
Crazy 19 5 Builders: Take the ceiling route, using the release rate for crowd control.